The cat is displaying serious signs of insecurity. He sits on my knee and starts to dig his claws in, doing this ad infinitum until it becomes unbearable. At one point today I lost my patience with him totally, smacked him on the nose and threw him on the floor. Unfortunately the dog was between him and the floor. She was a bit surprised. He is now staying well clear and I am enjoying the respite, though I doubt it will last long.
Funny how he is the same colour (and temperament) as Garfield.